Rule-Based System

A rule-based expert system attempts to capture knowledge of domain experts into expressions that can be evaluated known as rules; an example rule might read, "If the patient has high blood pressure, he or she is at risk for a stroke." Once enough of these rules have been compiled into a rule base, the current working knowledge will be evaluated against the rule base by chaining rules together until a conclusion is reached. Some of the advantages of a rule-based expert system are the fact that it makes it easy to store a large amount of information, and coming up with the rules will help to clarify the logic used in the decision-making process. However, it can be difficult for an expert to transfer their knowledge into distinct rules, and many rules can be required for a system to be effective.

Rule-based systems can aid physicians in many different areas, including diagnosis and treatment. An example of a rule-based expert system in the clinical setting is MYCIN. Developed at Stanford in the 1970s, MYCIN was based on around 600 rules and was used to help identify the type of bacteria causing an infection. While useful, MYCIN can help to demonstrate the magnitude of these types of systems by comparing the size of the rule base (600) to the narrow scope of the problem space.

The Stanford AI group subsequently developed ONCOCIN, another rules-based expert system coded in Lisp in the early 1980's . The system was intended to reduce the number of clinical trial protocol violations, and reduce the time required to make decisions about the timing and dosing of chemotherapy in late phase clinical trials. As with MYCIN, the domain of medical knowledge addressed by ONCOCIN was limited in scope and consisted of a series of eligibility criteria, laboratory values, and diagnostic testing and chemotherapy treatment protocols that could be translated into unambiguous rules. Oncocin was put into production in the Stanford Oncology Clinc.

from http://en.wikipedia.org/wiki/Clinical_decision_support_system#Rule-Based_System

Fact, Rules, Predicate, and Variable in Prolog

=-Animals Database -=

animal(mammal,tiger,carnivore,stripes).
animal(mammal,hyena,carnivore,ugly).
animal(mammal,lion,carnivore,mane).
animal(mammal,zebra,herbivore,stripes).
animal(bird,eagle,carnivore,large).
animal(bird,sparrow,scavenger,small).
animal(reptile,snake,carnivore,long).
animal(reptile,lizard,scavenger,small).

1.all the mammals

?- animal(mammal,A,_,_).

2.all the carnivores that are
mammals

?-animal(mammal,A,carnivore,_).

3.all the mammals with stripes

?- animal(mammal,A,_,stripes).

4.whether there is a reptile that has a
mane

?- animal(reptile,_,_,mane).

/* Dating Agency Database */

person(bill,male).
person(george,male).
person(alfred,male).
person(carol,female).
person(margaret,female).
person(jane,female).
couple(X,Y):-person(X,male),person(Y,female). ---->revision

Extend the program with a rule that defines a predicate couple with two
arguments, the first being the name of a man and the second the name of a woman.
Load your revised program into Prolog and test it.

?- couple(X,Y).